//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31110 SUBJECT: IceCube-211123A - IceCube observation of a high-energy neutrino candidate track-like event DATE: 21/11/24 03:30:28 GMT FROM: Marcos Santander at U. Alabama/IceCube The IceCube Collaboration (http://icecube.wisc.edu/) reports: On 2021-11-23 at 14:25:22.6 UT IceCube detected a track-like event with a moderate probability of being of astrophysical origin. The event was selected by the ICECUBE_Astrotrack_Bronze alert stream. The average astrophysical neutrino purity for Bronze alerts is 30%. This alert has an estimated false alarm rate of 2.567 events per year due to atmospheric backgrounds. The IceCube detector was in a normal operating state at the time of detection. After the initial automated alert (https://gcn.gsfc.nasa.gov/notices_amon_g_b/135930_15193553.amon, more sophisticated reconstruction algorithms have been applied offline, with the direction refined to: Date: 2021-11-23 Time: 14:25:22.6 UT RA: 265.52 (+3.14 -2.84 deg 90% PSF containment) J2000 Dec: 7.33 (+2.38 -2.48 deg 90% PSF containment) J2000 Both the initial alert and subsequent offline reconstructions were delayed as computing resources were undergoing maintenance. We encourage follow-up by ground and space-based instruments to help identify a possible astrophysical source for the candidate neutrino. Two gamma-ray sources listed in the 4FGL Fermi-LAT catalog, 4FGL J1736.6+0628 and 4FGL J1734.0+0805, are located within the 90% error region for the event, located 1.6 and 2.1 deg away from the best-fit position, respectively. The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector operating at the geographic South Pole, Antarctica. The IceCube realtime alert point of contact can be reached at roc@icecube.wisc.edu //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31112 SUBJECT: IceCube Alert 211123.60: Global MASTER-Net observations report DATE: 21/11/24 15:26:18 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, G.Antipov, D.Zimnukhov, V.Senik, T.Pogrosheva, E.Minkina, A.Chasovnikov, V.Topolev, V.Grinshpun, D.Kuvshinov, D. Cheryasov (Lomonosov Moscow State University, SAI, Physics Department), R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA), R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias), D. Buckley (South African Astronomical Observatory), O.A. Gres, N.M. Budnev (Irkutsk State University, API), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational State University) MASTER-Tavrida robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, SAI Crimea astronomical station) started inspect of the IceCube Alert 211123.60 (trigger No 15193553,17h 40m 35.28s , +07d 02m 38.4s, R=1.01) errorbox 81707 sec after notice time and 1 days 2636 sec after trigger time at 2021-11-24 15:09:18 UT, with upper limit up to 17.3 mag. Observations started at twilight. The observations began at zenith distance = 65 deg. The sun altitude is -10.7 deg. The galactic latitude b = 18 deg., longitude l = 31 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1794559 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 89066 | 2021-11-24 15:09:18 | MASTER-Tavrida | (17h 45m 12.09s , +04d 43m 42.5s) | C | 60 | 16.2 | 89303 | 2021-11-24 15:13:15 | MASTER-Tavrida | (17h 38m 04.47s , +04d 44m 59.8s) | C | 60 | 16.7 | 89540 | 2021-11-24 15:17:12 | MASTER-Tavrida | (17h 33m 35.03s , +06d 37m 18.6s) | C | 60 | 17.0 | 89619 | 2021-11-24 15:18:31 | MASTER-Tavrida | (17h 41m 44.87s , +06d 37m 29.3s) | C | 60 | 17.0 | 89699 | 2021-11-24 15:19:51 | MASTER-Tavrida | (17h 38m 28.19s , +08d 33m 02.5s) | C | 60 | 17.2 | 89777 | 2021-11-24 15:21:10 | MASTER-Tavrida | (17h 46m 33.72s , +08d 31m 22.8s) | C | 60 | 17.3 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31120 SUBJECT: IceCube-211123A: Upper limits from Fermi-GBM Observations DATE: 21/11/24 20:42:41 GMT FROM: Cori Fletcher at USRA C. Fletcher (USRA) reports on behalf of the Fermi-GBM team: For the IceCube high-energy neutrino candidate event IceCube-211123A (GCN 31110), at the event time Fermi-GBM was observing the reported neutrino location at: RA: 265.52 (+3.14 -2.84 deg 90% PSF containment) J2000 Dec: 7.33 (+2.38 -2.48 deg 90% PSF containment) J2000 There was no Fermi-GBM onboard trigger around the event time of the neutrino candidate. An automated, blind search for short gamma-ray bursts below the onboard triggering threshold in Fermi-GBM also identified no counterpart candidates. The GBM targeted search, the most sensitive, coherent search for GRB-like signals, was run from +/-30 s around the neutrino candidate time. From this search, no significant signal was found related to IceCube-211123A. We set upper limits on impulsive gamma-ray emission. Using the representative soft, normal, and hard GRB-like templates described in arXiv:1612.02395, we set the following 3 sigma flux upper limits over 10-1000 keV (in units of 10^-7 erg/s/cm^2): Timescale Soft Normal Hard ------------------------------------------- 0.128 s: 4.7 7.9 20. 1.024 s: 1.8 3.0 6.5 8.192 s: 0.47 0.88 1.6 These results are preliminary. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31121 SUBJECT: IceCube-211123A: INTEGRAL was inactive at the time of the event DATE: 21/11/24 20:45:10 GMT FROM: Volodymyr Savchenko at ISDC,U of Geneve V. Savchenko, C. Ferrigno (ISDC/UniGE, Switzerland) S. Mereghetti (INAF IASF-Milano, Italy) J. Rodi (IAPS-Roma, Italy) A. Coleiro (APC, France) on behalf of the INTEGRAL multi-messenger collaboration: https://www.astro.unige.ch/cdci/integral-multimessenger-collaboration The INTEGRAL spacecraft has a highly elliptical orbit and the instruments are not acquiring science data during perigee passage, every 2.6 days to prevent radiation-induced damages. Unfortunately, at the time of the IceCube-211123A (2021-11-23 14:25:22) the spacecraft was preparing to the start the observations after the perigee passage between the orbits number 2438 and 2439 and no scientific instrument data are available between 2021-11-23T08:09:55 and 2021-11-23T17:15:45. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31122 SUBJECT: IceCube-211123A: Upper limits from a search for additional neutrino events in IceCube DATE: 21/11/24 22:29:54 GMT FROM: Alex Pizzuto at ICECUBE/U of Wisconsin The IceCube Collaboration (http://icecube.wisc.edu/) reports: IceCube has performed a search [1] for additional track-like muon neutrino events arriving from the direction of IceCube-211123A (https://gcn.gsfc.nasa.gov/gcn3/31110.gcn3) in a time range of 1000 seconds centered on the alert event time (2021-11-23 14:17:02.600 UTC to 2021-11-23 14:33:42.600 UTC) during which IceCube was collecting good quality data. Excluding the event that prompted the alert, zero track-like events are found within the 90% containment region of IceCube-211123A. The IceCube sensitivity assuming an E^-2.5 spectrum (E^2 dN/dE at 1 TeV) to neutrino point sources within the locations spanned by the 90% spatial containment region of IceCube-211123A ranges from 1.3e-01 to 1.4e-01 GeV cm^-2 in a 1000 second time window. 90% of events IceCube would detect from a source at this declination with an E^-2.5 spectrum have energies in the approximate energy range between 3e+02 GeV and 1e+05 GeV. A subsequent search was performed including 2 days of data centered on the alert event time (2021-11-22 14:25:22.600 UTC to 2021-11-24 14:25:22.600 UTC). In this case, we report a p-value of 0.10, consistent with no significant excess of track events. The IceCube sensitivity assuming an E^-2.5 spectrum (E^2 dN/dE at 1 TeV) to neutrino point sources within the locations spanned by the 90% spatial containment region of IceCube-211123A ranges from 1.5e-01 to 1.6e-01 GeV cm^-2 in a 2 day time window. The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector operating at the geographic South Pole, Antarctica. The IceCube realtime alert point of contact can be reached at roc@icecube.wisc.edu. [1] IceCube Collaboration, R. Abbasi et al., ApJ 910 4 (2021) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31123 SUBJECT: Fermi-LAT Gamma-ray Observations of IceCube-211123A DATE: 21/11/25 09:57:15 GMT FROM: Simone Garrappa at DESY S. Garrappa (DESY-Zeuthen), S. Buson (Univ. of Wuerzburg) and R. de Menezes (Univ. of Wuerzburg, Univ. of Sao Paulo) on behalf of the Fermi-LAT collaboration: We report an analysis of observations of the vicinity of the high-energy IC211123A neutrino event (GCN 31110) with all-sky survey data from the Large Area Telescope (LAT), on board the Fermi Gamma-ray Space Telescope. The IceCube event was detected on 2021-11-23 at 14:25:22.6 UT (T0) with J2000 position RA = 265.52 (+3.14, -2.84) deg, Decl. = 7.33 (+2.38, -2.48) deg (90% PSF containment). Four cataloged gamma-ray (>100 MeV) sources are located within the 90% IC211123A localization region (4FGL-DR2, The Fermi-LAT collaboration 2020, ApJS, 247, 33). One of these, 4FGL J1751.5+0938, associated with the BL Lac object OT 081, is also listed in the 3FHL catalog as 3FHL J1751.5+0938 (Ajello et al. 2017, 232, 18). We searched for intermediate (days to years) timescale emission from a new gamma-ray transient source. Preliminary analysis indicates no significant (> 5 sigma) new excess emission (> 100 MeV) at the IC211123A best-fit position. Assuming a power-law spectrum (photon index = 2.0 fixed) for a point source at the IC211123A best-fit position, the >100 MeV flux upper limit (95% confidence) is < 2.4e-10 ph cm^-2 s^-1 for ~13-years (2008-08-04 to 2021-11-23 UTC), and < 7.4e-9 (< 8.5e-8) ph cm^-2 s^-1 for a 1-month (1-day) integration time before T0. Since Fermi normally operates in an all-sky scanning mode, regular monitoring of this source will continue. For these observations the Fermi-LAT contact persons are S. Garrappa (simone.garrappa at desy.de) and S. Buson (sara.buson at uni-wuerzburg.de). The Fermi-LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden.